In 2010, MBTA approved the purchase of 20 new diesel-electric locomotives from Wabtec subsidiary MotivePower, Inc. for $114 million. At the time, they were slated to replace the 20 oldest units in the fleet.

On top of seven units added in 2012, in June MBTA signed a contract with MotivePower for 13 additional units, bringing the overall total to 40. The recent contract is valued at $70 million.

Industrial designer Cesar Vergara of VergaraStudio designed the HSP-46’s carbody, as well as several potential paint schemes, which the MBTA had members of the riding public vote on in 2012. The scheme that was ultimately selected was by far the largest vote-getter.